Wingtip vortices are swirling air patterns that form at the tips of an aircraft’s
wings due to the pressure difference between the upper and lower surfaces of
the wing during flight.
Induced drag is a type of drag that happens because of lift
1. Form drag – Caused by the shape of the aircraft (e.g. fuselage, landing
gear).
2. Skin friction – Air rubbing against the aircraft’s surface.
3. Interference drag – Airflows crashing into each other at joints (like wing-
body connections).
Swept-back Wing:
• Wing is slanted backward (like a boomerang).
• Airflow doesn’t hit the wing straight on, especially at
the tips — it kind of “slides” along the span.
• The tips stall first because:
• Air slows down there.
• They have less effective airflow.
• When the tip stalls, lift moves forward, so CP moves
forward.
Why it’s annoying?
• Tip stall = aileron (which is at the tip) becomes useless
or worse, reverses. That’s bad news in a stall.
Rectangular Wing:
• Simple straight wing — same width all the way.
• The root stalls first:
• Because the root has more load and less efficient
airflow.
• Since the tips still make lift, CP shifts backward.
Why it’s safer?
• Tips are the last to stall, so ailerons still work longer =
better control during stall.
⸻
• Swept-back: Tips stall first → CP moves forward.
• Rectangular: Root stalls first → CP moves back.
, A spin happens when the plane stalls unevenly and starts spiraling nose-down Asymmetric Airfoil
uncontrollably. - Center of pressure moves with changes in angle of attack.
Caused by: Symmetric Airfoil
• Exceeding the critical angle of attack on both wings. - Center of pressure stays fixed.
• Uncoordinated flight (usually during a stall with too much rudder input).
Phases of a spin:
1. Entry – the plane stalls and begins to yaw.
2. Incipient spin – the rotation begins.
3. Fully developed spin – the aircraft follows a stable, spiraling descent.
Recovery – actions are taken to break the spin and regain control.
Recovery technique (PARE method):
• Power to idle
• Ailerons neutral
• Rudder opposite the spin direction
• Elevator forward (to break the stall)
Aspect Ratio
• Ratio of wingspan to average chord (width).
• High aspect ratio = long, narrow wings (better efficiency).
• Low aspect ratio = short, wide wings (better maneuverability).
Taper Ratio
• Ratio of tip chord to root chord.
• Describes how much the wing narrows from root to tip.
Flaps help the plane take off and land in a shorter distance by
adding lift and drag. But when you extend flaps, the center of
pressure (CP) moves aft—towards the back of the wing. This shift
pushes the nose down.
During Landing:
- First, the leading edge flaps are extended to help delay the wing’s stall
and improve stability at slower speeds.
- After that, the trailing edge flaps are extended to increase lift and drag, Wing Fences
helping the aircraft slow down and maintain a stable descent. • Vertical surfaces on the wing.
• Help control airflow, preventing it from moving sideways (spanwise).
After Takeoff (When Retracting): • Improve handling at high angles of attack and delay stall.
- First, the trailing edge flaps are retracted, followed by the leading edge
flaps.
- This helps reduce drag gradually and ensures a smooth transition without High-speed buffet
a sudden loss of lift or excessive nose drop. - When the airplane starts shaking because it’s flying too fast. This happens when air
moves so quickly over the wings that shock waves form, making the airflow messy
and causing the plane to vibrate.
Gust Load Factor:
Rectangular Wings (straight, unswept): - When the plane hits a sudden strong wind (gust), it feels extra “weight” or force.
• These wings have a more uniform lift distribution, especially when un- - If the gust load factor increases (stronger gust or faster speed), the plane feels
tapered. heavier — it can stress or damage the structure if too much.
• The aerodynamic center (where CP tends to stay) is roughly at the quarter- - If the gust load factor reduces (weaker gust or slower speed), the plane feels
chord point (25% of the chord) and relatively farther back on the chord. lighter and safer.
• So, CP appears aft (toward the rear) of the wing. - At higher altitudes, the air is thinner, so gusts are not as strong — gust load
factors are smaller up high.
Swept Wings: - If the plane has higher wing loading (heavier aircraft or smaller wings), it feels
• Swept wings behave differently. The airflow doesn’t hit the wing straight gusts less because it’s harder for the wind to push a heavier plane around.
on—some of it flows spanwise (along the wing) instead of chordwise.
• This changes the effective lift distribution, with more lift happening closer Gust Envelope:
to the root of the wing. - This is like a safety map that shows how much gust (sudden wind) the plane can
• This causes the center of pressure to shift forward. handle at different flying speeds.
• Also, due to how the wing stalls (typically starting from the tip), designers - If the pilot flies inside the gust envelope, the plane is safe, even if it hits gusts.
keep the CP forward for stability and controllability, especially at high - If the pilot flies outside (too fast or too strong gust), the plane could be damaged
speeds. or lose control.
wings due to the pressure difference between the upper and lower surfaces of
the wing during flight.
Induced drag is a type of drag that happens because of lift
1. Form drag – Caused by the shape of the aircraft (e.g. fuselage, landing
gear).
2. Skin friction – Air rubbing against the aircraft’s surface.
3. Interference drag – Airflows crashing into each other at joints (like wing-
body connections).
Swept-back Wing:
• Wing is slanted backward (like a boomerang).
• Airflow doesn’t hit the wing straight on, especially at
the tips — it kind of “slides” along the span.
• The tips stall first because:
• Air slows down there.
• They have less effective airflow.
• When the tip stalls, lift moves forward, so CP moves
forward.
Why it’s annoying?
• Tip stall = aileron (which is at the tip) becomes useless
or worse, reverses. That’s bad news in a stall.
Rectangular Wing:
• Simple straight wing — same width all the way.
• The root stalls first:
• Because the root has more load and less efficient
airflow.
• Since the tips still make lift, CP shifts backward.
Why it’s safer?
• Tips are the last to stall, so ailerons still work longer =
better control during stall.
⸻
• Swept-back: Tips stall first → CP moves forward.
• Rectangular: Root stalls first → CP moves back.
, A spin happens when the plane stalls unevenly and starts spiraling nose-down Asymmetric Airfoil
uncontrollably. - Center of pressure moves with changes in angle of attack.
Caused by: Symmetric Airfoil
• Exceeding the critical angle of attack on both wings. - Center of pressure stays fixed.
• Uncoordinated flight (usually during a stall with too much rudder input).
Phases of a spin:
1. Entry – the plane stalls and begins to yaw.
2. Incipient spin – the rotation begins.
3. Fully developed spin – the aircraft follows a stable, spiraling descent.
Recovery – actions are taken to break the spin and regain control.
Recovery technique (PARE method):
• Power to idle
• Ailerons neutral
• Rudder opposite the spin direction
• Elevator forward (to break the stall)
Aspect Ratio
• Ratio of wingspan to average chord (width).
• High aspect ratio = long, narrow wings (better efficiency).
• Low aspect ratio = short, wide wings (better maneuverability).
Taper Ratio
• Ratio of tip chord to root chord.
• Describes how much the wing narrows from root to tip.
Flaps help the plane take off and land in a shorter distance by
adding lift and drag. But when you extend flaps, the center of
pressure (CP) moves aft—towards the back of the wing. This shift
pushes the nose down.
During Landing:
- First, the leading edge flaps are extended to help delay the wing’s stall
and improve stability at slower speeds.
- After that, the trailing edge flaps are extended to increase lift and drag, Wing Fences
helping the aircraft slow down and maintain a stable descent. • Vertical surfaces on the wing.
• Help control airflow, preventing it from moving sideways (spanwise).
After Takeoff (When Retracting): • Improve handling at high angles of attack and delay stall.
- First, the trailing edge flaps are retracted, followed by the leading edge
flaps.
- This helps reduce drag gradually and ensures a smooth transition without High-speed buffet
a sudden loss of lift or excessive nose drop. - When the airplane starts shaking because it’s flying too fast. This happens when air
moves so quickly over the wings that shock waves form, making the airflow messy
and causing the plane to vibrate.
Gust Load Factor:
Rectangular Wings (straight, unswept): - When the plane hits a sudden strong wind (gust), it feels extra “weight” or force.
• These wings have a more uniform lift distribution, especially when un- - If the gust load factor increases (stronger gust or faster speed), the plane feels
tapered. heavier — it can stress or damage the structure if too much.
• The aerodynamic center (where CP tends to stay) is roughly at the quarter- - If the gust load factor reduces (weaker gust or slower speed), the plane feels
chord point (25% of the chord) and relatively farther back on the chord. lighter and safer.
• So, CP appears aft (toward the rear) of the wing. - At higher altitudes, the air is thinner, so gusts are not as strong — gust load
factors are smaller up high.
Swept Wings: - If the plane has higher wing loading (heavier aircraft or smaller wings), it feels
• Swept wings behave differently. The airflow doesn’t hit the wing straight gusts less because it’s harder for the wind to push a heavier plane around.
on—some of it flows spanwise (along the wing) instead of chordwise.
• This changes the effective lift distribution, with more lift happening closer Gust Envelope:
to the root of the wing. - This is like a safety map that shows how much gust (sudden wind) the plane can
• This causes the center of pressure to shift forward. handle at different flying speeds.
• Also, due to how the wing stalls (typically starting from the tip), designers - If the pilot flies inside the gust envelope, the plane is safe, even if it hits gusts.
keep the CP forward for stability and controllability, especially at high - If the pilot flies outside (too fast or too strong gust), the plane could be damaged
speeds. or lose control.
